<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title></title>
</head>
<body>
  <div id="app">
     <p>选择所在的城市:</p>
     <select name="city" v-model="city">
       <option value="上海">上海</option>
       <option value="北京">北京</option>
       <option value="南京">南京</option>
     </select>
     <p>选择的城市是: {{city}}</p>

     <p>----------------------------</p>

    <p>选择所在的城市:</p>
    <select name="cities" v-model="cities" multiple>
      <option value="上海">上海</option>
      <option value="北京">北京</option>
      <option value="南京">南京</option>
    </select>
    <p>选择的城市是: {{cities}}</p>
  </div>
  <script src="js/vue.js"></script>
  <script>
    const app = Vue.createApp({
      data() {
        return {
           city: '北京',
           cities: []
        }
      }
    }).mount('#app');
  </script>
</body>
</html>
